Swimmers are being urged to take precautions against a chlorine-resistant parasite known for making swimmers sick.

The presence of chlorine-resistant parasites appears to be increasing, according to a new report from the Centres for Disease Control and Prevention

There were more than 13,000 reported cases of cryptosporidiosis, a watery diarrhea that can last up to three weeks in some patients, in Canada between 2010 and 2016.

Cryptosporidiosis is caused by the cryptosporidium parasite, which lives in the intestines of infected people and animals. It generally just makes the infected person sick, but can be life-threatening for people withweakened immune systems.

The parasite can survive in chlorinated water for up to a week.

So should swimmers in B.C. be worried about "crypto?"

The CDC says there were 88 cases in the province in 2017, the most recent data available.

Health officials say the best way to avoid getting sick is to avoid public pools, especially if they're already ill.

Those who still decide to go for a dip should shower before and after swimming, and make sure they wash their hands before eating.

With files from CTV News Vancouver Island